
public class Main {
    public static void main(String[] args) {
        int a = Integer.parseInt(args[0]);
        int b = Integer.parseInt(args[1]);
        System.out.println("结果是：" + (a + b));
    }
}

public class Main {
    public static void main(String[] args) {
        int a = Integer.parseInt(args[0]);
        int b = Integer.parseInt(args[1]);
        System.out.println((a + b));
    }
}

class Main {
    public static void main(String[] args) {
        int a = args[0];
        System.out.println(reverse(a));
    }

    public static int reverse(int x) {
        int rev = 0;
        while (x != 0) {
            if (rev < Integer.MIN_VALUE / 10 || rev > Integer.MAX_VALUE / 10) {
                return 0;
            }
            int digit = x % 10;
            x /= 10;
            rev = rev * 10 + digit;
        }
        return rev;
    }
}
798720
import java.util.HashMap;

class Main {
    public static void main(String[] args) {
        String s = args[0];
        System.out.println(lengthOfLongestSubstring(s));
    }

    public static int lengthOfLongestSubstring(String s) {
        if (s.isEmpty()) return 0;
        HashMap<Character, Integer> map = new HashMap<Character, Integer>();
        int max = 0;
        int left = 0;
        for(int i = 0; i < s.length(); i ++){
            if(map.containsKey(s.charAt(i))){
                left = Math.max(left,map.get(s.charAt(i)) + 1);
            }
            map.put(s.charAt(i),i);
            max = Math.max(max,i-left+1);
        }
        return max;

    }
}
